The present invention relates to a radar system and more particularly to a radar system that will detect coherent or hard targets and which will discriminate against random or incoherent targets, particularly sea clutter. The present invention purposely codes a transmitted radar signal so that a hard target can be considered as part of the overall system and modifies the return signal or echo so that a radar receiver can enhance the hard target echo.
Clutter, such as echoes from innumerable surface waves, can be particularly bothersome sometimes in radar receivers as clutter is numerous echoes from unwanted objects that obscure a wanted echo signal. The unwanted echo signals confuse the scope picture, or presentation, sufficiently to make an observer's task difficult. While various systems have been developed to reduce the undesirable effects of clutter, such as by use of extremely short pulses, or by pulse compression, these heretofore known systems have not utilized the action of a hard target in distinguishing coherent targets from undesirable clutter.